Suppress Warnings on circular foreign keys and hypertables during dump

[davidkohn88]

They cause unnecessary confusion

[davidkohn88]

These may be safely disregarded for now, it's a bit difficult to remove the messages as they are multi-line and determining whether the warnings are ones that can be disregarded or not is a bit difficult, would have to rewrite some of the filtering stuff to do multi-line processing, which takes a bit more effort...